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Exercise 11.4 Nonmetal as Acids

1. When coal or oil containing compounds is burned, is produced. The sulfur dioxide reacts with dioxide (another pollutant) to give sulfur trioxide and nitrogen monoxide. All of these pollutants are gases. Sulfur trioxide reacts with water to give . When this happens in the atmosphere, forms. (a) In the mid-1990s, fossil fuel (power plants, vehicles, etc.) and industry were releasing sulfur oxides containing 70 Tg S per year. (1 Tg = 1 million tonnes = 1012 g). Calculate the mass of each of the following:

i. SO2 containing 70 Tg S

ii. SO3 containing 70 Tg S

iii. H2SO4 containing 70 Tg S

(b) Draw a balanced chemical equation for the reaction of sulfur trioxide with water (using Lewis diagrams not molecular formulas). Use curly arrows to show the movement of electrons in the first step on this reaction. You do not have to show how the H moves.

(c) Sulfur trioxide is behaving as what type of acid in this reaction?

(d) What are the oxidation states of sulfur in sulfur trioxide and sulfuric acid? (e) A cap-and-trade scheme has significantly reduced the amount of sulfur oxides released into the atmosphere; however, we are still releasing substantial amounts of a different nonmetal dioxide. In 2010, annual global emissions were 33 618 Tg CO2. 30-40% of this is dissolved in the oceans.

Describe the consequences of continuing to dissolve substantial amounts of CO2 in the ocean every year (considering that many creatures at the base of the ocean food web have shells made of CaCO3). Use chemical equations where appropriate.